Smoke evacuation system

ABSTRACT

A smoke evacuating system for use during surgical procedures, particularly minimally invasive procedures involving the use of a laser or cautery at a surgical site having an associated higher than ambient pressure, wherein the system includes a filter with a site side and an outlet side and a fluid conduit extending between the surgical site and the filter. The filter includes a filter media and a housing substantially surrounding the filter media with a space between the filter media and the housing to collect condensed vapor. The filter exhibits low resistance or a low pressure drop and resists fluid flow, whereby the higher than ambient pressure is not substantially diminished and generates a fluid flow in the fluid flow path tending to carry smoke to and through the filter.

The present application is a continuation of U.S. application Ser. No.09/544,695, filed Apr. 7, 2000 now U.S. Pat. No. 6,589,316, which was acontinuation-in-part of U.S. application Ser. No. 09/046,265, filed Mar.23, 1998 now U.S. Pat. No. 6,110,259, which claims the priority benefitof a U.S. provisional application, Ser. No. 60/066,331, filed Nov. 21,1997.

FIELD

The present invention relates to smoke removal and filtering and, moreparticularly, to a smoke evacuation system for use in surgicalprocedures, including minimally invasive surgical procedures such aslaparoscopy, during which cautery or a laser is used.

BACKGROUND

U.S. Pat. No. 5,578,000 (Greff et al.) discloses a smoke evacuationsystem including a trocar having a working channel, a stopcock or valvecommunicating with the channel, a source of wall vacuum, a fluid conduitconnected between the stopcock of the trocar and the source of wallvacuum, a first filter for applying a first reduction in suction andseparating smoke into its components and a residual gas, and a flowrestriction to generate a second reduction in suction. The flowrestriction is along a passage formed by the conduit, the filter andworking channel.

Greff et al. note that smoke has been handled by simply allowing it toescape into the operating room, thereby subjecting the surgeon and staffto contaminants. They recognize that closed, recirculating systemsinvolving two trocars have been used, as have probes which are insertedthrough a trocar, but that such systems do not adequately solve theproblems associated with smoke and the removal thereof, e.g.,contamination, smell and impaired visibility of a surgical site.

Other problems inadequately addressed by currently available evacuationsystems are loss of the pressure in the pneumoperitoneum, and/or tissuedrying, particularly if pressure loss is compensated for by increasinginsufflation gas flow.

While the smoke evacuation system disclosed in the Greff et al. patentmay be well suited for its intended purpose, it would be advantageous ifthe dependency on a remote, “in-wall” vacuum source could be eliminatedthereby reducing the cost and complexity of the system.

SUMMARY

The present invention provides an improvement over currently known smokeevacuation systems, methods and techniques, including laparoscopic smokeevacuation systems such as the system disclosed in the Greff et al.patent.

In one embodiment, the present invention provides a smoke evacuatingsystem for use during surgical procedures comprising a filter foroperable coupling to a surgical site, said filter exhibiting a pressuredrop ranging from approximately 0.5 to 20 mm/Hg, with a preferredpressure drop ranging from approximately 1 to 3 mm/Hg. The filter may becoupled directly to the patient.

In another embodiment, the present invention provides a smoke evacuatingsystem for use during surgical procedures, particularly minimallyinvasive procedures, involving a surgical site having an associatedhigher than ambient pressure, wherein the system comprises a filter witha inlet side (the side generally closest to the surgical site) and anoutlet side and a fluid conduit extending between the surgical site andthe filter. The fluid conduit defines a substantially unobstructed fluidflow path between the surgical site and filter, and the higher thanambient pressure and a pressure drop associated with the filter generateand enable a fluid flow in the fluid flow path, the filter causing a lowpressure drop (i.e., pressure differential from side to side) in thefluid flow from the inlet side to the outlet side.

In yet another embodiment, the present invention provides a smokeevacuating system for use during surgical procedures, particularlyminimally invasive procedures, including a conduit for operable couplingto a surgical site, said conduit operably carrying a filter exhibiting apressure drop ranging from approximately 1 to 3 mm/Hg and defining asubstantially unobstructed fluid flow path between the surgical site andthe filter. The conduit may include a connector for being connected to atrocar or other tubular member. An on/off valve may be incorporated tocontrol the flow of fluid through the conduit, whereby, when the valveis open, the flow path from the surgical site to the filter issubstantially unobstructed.

An advantage of the present invention is that it eliminates dependencyon a built-in, in wall vacuum source. It does not require high vacuumsuction and the requisite high resistance filters or combination of flowrestrictors or reducers and filters. Further, it simplifies smokeevacuation and filtering by eliminating the need for multiple, in-linestructures (filters, resistors, etc.) for stepping down or reducingsuction.

While the present invention may be used in surgical procedures, it mayalso be used in industry to remove smoke and/or chemicals from areassuch as workstations. For example, it might be used at or adjacent tochip or electronic equipment manufacturing stations to reduce workers'exposure to smoke produced as connections are formed. Similarly, itmight be used to reduce exposure to etching chemicals.

A feature of the present invention is a balanced smoke evacuation systemwherein a filter with a relatively low pressure drop performs afiltering function and a flow regulating function, helping to preservethe pressure at or in a pressurized surgical site such as a laparoscopywith a pneumoperitoneum while providing for sufficient flow therefrom toremove smoke from the site, thereby reducing the need for substantial orconstant reinsufflation of the surgical site.

Surgical aerosols, or bio-aerosols, include smoke from burning tissue,but also often include moisture, steam or mist produced by cells as theyare heated and/or ruptured by certain surgical instruments such aslasers or ultrasonic scissors (e.g., “Harmonic Scissors” by Ethicon).Additionally, some surgeons are now using heated, humidified gas forinsufflation to help maintain a normal body temperature and to helpreduce tissue dessication. One embodiment of the invention is adaptedfor use in surgical procedures during which surgical aerosols,particularly moist or moisture containing aerosols, are produced and/orin which heated and/or humidified gas is used by including a space orregion into which moisture can move, gather and/or be collected withoutdiminishing flow rate or the efficiency of the filter.

Another embodiment of the invention includes an elbow member adapted tobe coupled between a trocar and the conduit to position the conduit toreduce any potential inconvenience to the surgeon and/or staff during aprocedure.

An advantage of the smoke evacuation system of the present invention isthat it provides for the intra-operative or intra-procedural evacuationand filtration of smoke from a pressurized surgical site, e.g., theabdominal cavity, without requiring suction and without rapidlyexhausting the pressurizing gas or causing a substantial pressurereduction at the pressurized surgical site. Other advantages are thatthe invention does not require an operator, it continuously removessmoke from the pressurized cavity (once the valve in valved embodimentsis opened) to improve visibility without venting, it reduces operatingtime, it eliminates surgical smoke from the operating room, therebyreducing the health risk stemming from exposure to such smoke, iteliminates the need to apply suction to a patient thereby reducingpotential tissue damage, and it is inexpensive.

Other features and advantages of the smoke evacuating apparatus andmethod of the present invention will become more fully apparent andunderstood with reference to the following description and drawings, andthe appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts one embodiment of the smoke evacuation system of thepresent invention.

FIG. 2 depicts the filter of one embodiment of the present invention.

FIG. 3 depicts a portion of the filter of FIG. 2 in cross section.

FIG. 4 depicts another embodiment of the filter.

FIG. 5 depicts a connector stopcock or valve for use in the smokeevacuation system of the present invention.

FIG. 6 depicts, largely representationally, a trocar (and obturator) ofa type suitable for use with the present.

FIG. 7 depicts an elbow connector connecting a trocar and a valveconnector.

FIG. 8 depicts another embodiment of the filter.

FIG. 9 depicts another embodiment of the smoke evacuation system of thepresent invention.

FIG. 10 depicts another embodiment of the smoke evacuation system of thepresent invention.

FIG. 11 depicts the filter of one embodiment of the present inventioncoupled to a surgical site.

FIG. 12 depicts a portion of one embodiment of the filter of theinvention in cross section.

DESCRIPTION

The accompanying Figures depict embodiments of the smoke evacuationapparatus or system of the present invention, and features andcomponents thereof. With regard to means for fastening, mounting,attaching or connecting the components of the present invention to formthe apparatus as a whole, unless specifically described otherwise, suchmeans are intended to encompass conventional fasteners such as machinescrews, machine threads, snap rings, hose clamps such as screw clampsand the like, rivets, nuts and bolts, toggles, pins and the like.Components may also be connected by friction fitting, or by welding ordeformation, if appropriate. Unless specifically otherwise disclosed ortaught, materials for making components of the present invention areselected from appropriate materials such as metal, metallic alloys,natural or synthetic fibers, plastics and the like, and appropriatemanufacturing or production methods including casting, extruding,molding and machining may be used. The components of the invention maybe constructed from any such suitable materials for use in surgicalrooms or in surgical procedures.

Any references to front and back, right and left, top and bottom, upperand lower, and horizontal and vertical are intended for convenience ofdescription, not to limit the present invention or its components to anyone positional or spacial orientation.

Referring to the Figures, particularly FIG. 1, the present inventionprovides a smoke evacuating system 14 for use during surgicalprocedures. The system 14 includes a filter 16 and a generally flexiblefluid conduit 18 connected to the filter 16. The conduit 18 may beprovided in one or more pieces. The system 14, particularly the end ofthe conduit 18, may include an integral or attachable male or femaleconnector (of the type well known in the art) for facilitating theconnection of the conduit 18 to the exhaust port or vent valve of atrocar, or the system 14 may include a Leur lock-type valve 17 (see FIG.5) operably coupled to the conduit 18, and it may include a generallytubular member 20, such as a typical well known trocar with an exhaustport (not shown).

Referring to FIG. 3, the filter 16 comprises a housing 24 with an inletconnector 26 and an outlet connector 28. Stepped hose barb typeconnectors may be used, as depicted in the Figures. The housing 24 maybe made from polypropylene or other suitable material. The housing 24contains the filter media 32, which comprises two thin, flat circular,disk shaped layers 34, 36. One layer 36, the layer adjacent to theoutlet connector 28, is formed of 0.2 μm hydrophobic 200 mg/square cmPTFE, and the other layer 34 is made of a 200 g/square m 50%cellulose/carbon fiber blend. The layers 34, 36 are immediately adjacentto each other and each has a large surface area. Together, they form afilter media 32 having a surface area generally corresponding to itsfiltration area, i.e., approximately 7.5 square cm, approximately 100times larger than the cross sectional area of the lumen of the depicted¼ inch conduit 18. Although a disk-shaped filter is depicted, othershapes may be used as long as a pressure drop suitable for low flow, lowpressure filtering is achieved. The filter 24, one or both layers, maybe designed to exhibit a “change filter” color change indicative thatuseful life of the filter is over or nearly over. The odor removinglayer 34 may be formed by or incorporate carbon or charcoal basedmaterial, or a diatomaceous earth material or other odor removing orreducing agent may be used.

The filter media 32 is potted or contained in the housing 24. Thehousing 24 has an inlet manifold 26 and an outlet manifold 28. On eachside of the filter media 32, in the respective manifolds, the housinghas a plurality of annular grooves 42. The housing 24 may be formedaround the filter media 32, or it may be formed in pieces which arejoined to pot the media 32. An alternative, button or rivet-likeembodiment of the filter 16, wherein the outlet 28 is substantiallyreduced to an outlet port 28′, is depicted in FIG. 4. This embodiment ofthe filter 16 may be carried at the free end of the conduit 18 or it, ora similar embodiment with a suitable protruding inlet connector forextending through the abdominal wall, may be coupled directly to theabdomen of a patient, for example, through a needle stick or othersuitable opening.

Referring to FIG. 12, in one embodiment, a space 55 may be providedbetween the housing 24 and the filter media 32. This space 55, which mayalso be referred to as a water trap, provides an area in which moistureand/or condensed vapor may collect during use of the system and filterof the present invention. In some applications, such as high smoke,laser, or harmonic scalpel procedures, a substantial amount of watervapor may be produced along with smoke. Although the filter media 32 orfilter paper may be made from hydrophobic material, in some highvapor-producing procedures, the filter media 32 may be unable to shedthe water or vapor that condenses because there is little or no space orarea for the moisture or liquid to move to and/or settle into. In anembodiment of the invention containing a space 55 between the filtermedia 32 and the housing 24, the space 55 provides an area or region inwhich water vapor can condense and settle without effecting theefficiency of the filter. FIG. 12 depicts one embodiment of a filterhaving a space 55 between the filter media 32 and the housing 24. Thespace 55 may be provided in a variety of orientations and locations withrespect to the filter media 32 and the housing 24. For instance, thespace 55 may be near the filter media 32 on the inlet 26 side of thehousing 24 or, in other embodiments, on the outlet 28 side of thehousing 24, or both. In addition, the space 55 may be near the outerand/or peripheral portions or regions 57 of the filter media 32 andhousing 24. The space 55 may also have a variety of geometries indifferent embodiments of the invention, and it may be provided in one ormore locations. In one embodiment of the invention, such as thatdepicted in FIG. 12, more than one space 55 may exist. FIG. 12, forinstance, shows spaces 55 near the outer portions 57 of the housing, onthe inlet side of the filter media 32, and on the outlet side of thefilter media. This is advantageous because it provides for liquidcollection spaces 55 which will be effective despite how the system maybe positioned or oriented during a surgical procedure. FIG. 12 depictscondensed vapor 61 collecting in the space 55 near the inlet side of thefilter media 32.

The system 14 provides a substantially unobstructed fluid flow paththrough the fluid conduit 18 between a valve 18 and filter 16 and, whenthe valve 18 is open, between a pressurized surgical site “S” and thefilter 16. The filter 16 provides flow regulation of a fluid(insufflation gas carrying smoke) flowing along the fluid flow path inthat it provides resistance to flow, whereby flow rates in someembodiments range from one (1) to four (4) liters/minute and, in otherembodiments, range from 1 to 3.8 liters/minute. The filter 16 exhibitsor has an associated pressure drop from one side to the other of fromapproximately one-half (0.5) to twenty (20) mm of mercury, with apressure drop of from approximately two (2) to three (3) mm of mercurybeing preferred in another embodiment, and a pressure drop ofapproximately one (1) mm of mercury being preferred in yet anotherembodiment. The latter pressure drops correspond generally to flow ratesof 1.8 liters/minute and 3.6 to 3.8 liters/minute, respectively. Higherpressures and/or lower pressure drops will produce higher correlativeflow rates, and the filter 16 may be available in several specificationsto be matched with the patient, function or procedure involved. The sizeand length of the fluid conduit or tube 18 may be varied to assist inproviding desired flow characteristics (approximately 1.0 to 30 litersper minute) in conjunction with the resistance or pressure drop of thefilter 16 of the present invention. The filter, therefore, may bedesigned for low flow applications, medium flow applications, or highflow applications. For instance, the filter 16 may operate at flow ratesof about 0.2 to 30 liters per minute when coupled to pressurizedsurgical sites, wherein pressure drops of approximately 0.5 to 30 mm Hgexist.

In one embodiment, the invention may be a “passive” smoke evacuationsystem and method. In this embodiment, the filter 16 may be designed toregulate the flow of smoke and gases from a surgical site to the ambientair outside a patient's body without the use of a vacuum supply. Thefilter 16, in this embodiment, is designed to have a pressure drop at anassociated flow rate sufficient to evacuate smoke from the pressurizedcavity to the ambient air outside of the cavity without loss ofpneumoperitoneum. For instance, in one embodiment, the filter 16 mayhave a resistance such that it causes a fluid flow rate of fromapproximately 0.2 to 30 liters per minute when coupled to a pressurizedsurgical site, wherein a pressure drop of approximately 0.5 to 30 mm Hgis maintained from the surgical site to ambient air, and wherein thefluid flow is induced as a result of the pressure in the pressurizedsurgical site. In other embodiments, the filter 16 may have a resistancesuch that a fluid flow rate of from about 1 to 20 liters per minuteresults at an associated pressure drop of from about 0.5 to 20 mm Hg.

In some embodiments, the tube 18 may be four to six feet in length, witha length of from 1.5 to 3.0 feet being preferred. If quarter inch tubingis selected, the lumen of the tube 18 typically would be 3 mm indiameter, but inner diameters ranging from 2 to 12 mm may be used. Theparameters of diameter and length of tube 18, size of trocar (for onepreferred example, 3 mm), and the resistance or pressure drop associatedwith filter 16 may be relatively adjusted to accommodate differentpatients, surgical procedures and/or operating room settings, as long asadequate low pressure, low flow smoke filtering and odor removal isachieved. The present invention may be embodied in a completelydisposable, single use unit or components thereof, e.g., the filter ortubing, may be disposable with other component reusable. Typically, thetrocar 20 or tubular member to which the conduit 18 is coupled, eitherdirectly or through an exhaust port or valve, is grounded to eliminateany errant current.

The present invention encompasses a method for evacuating smoke from asurgical site, particularly from a minimally invasive site such as alaparoscopy with a pneumoperitoneum. For example, for evacuating smokefrom a surgical site in the abdominal cavity during a laparoscopicprocedure, the method of the present invention comprises the steps ofoperably coupling a conduit 18 to the pneumoperitoneum, for example tothe tubular member 21 (FIG. 7) extending from the pneumoperitoneum, andcoupling a filter 16 having a low pressure drop there across to theconduit 18, whereby there is a substantially unobstructed, low volumefluid flow path between the pneumoperitoneum and the filter 18, wherebyparticulate material and odor are removed from the fluid. The fluid isinduced to flow through the conduit 18 and filter 16 by the generallycomplementary pressure of the insufflating gas of the pneumoperitoneumand the pressure drop of the filter 16. In one embodiment, the flow maybe controlled, e.g., initiated, stopped or reduced by incorporating avalve (such as a Leur lock valve (FIG. 5) or the like) with the conduit18 or by using a valved trocar or the like.

The apparatus and method of the present invention may be used inlaparoscopic procedure involving a pneumoperitoneum, i.e., a conditionin which air or gas is collected or insufflated into the peritonealcavity, but it also may be used in any other surgical procedureinvolving a substantially enclosed and/or pressurized surgical site suchas thoracoscopy. Referring to FIG. 10, in one embodiment, the conduit 18may be fitted with flow generating device 48 such as an in-line bloweror impeller, which may be battery powered such as some commerciallyavailable models, for drawing air, smoke, particulate matter andcontaminants into the conduit for filtration, whereby the invention maybe used for “open” surgical procedures. In this embodiment, the selectedflow generating device 48 may be located on either side of the filter16, although positioning it on the outlet side of the filter 16 mayprotect it from contaminants and, in non-disposable embodiments,lengthen its useful life. The flow generating device 48 may beincorporated with the filter 16 itself, for example, in the outletconnector. With reference to FIGS. 9 and 10, for use in open sitesurgical procedures, the site or intake end of the conduit 18 may beexpanded as at 19 and provided with a grille 21. In this embodiment theexpanded end 19 may be, for example, inserted partially into a deepwound or connected to a patient's body near a surgical site (e.g., byusing adhesive, straps, sutures or the like).

The present invention may be embodied in other specific forms withoutdeparting from the essential spirit or attributes thereof. It is desiredthat the embodiments described herein be considered in all respects asillustrative, not restrictive, and that reference be made to theappended claims for determining the scope of the invention.

1. A smoke evacuating system for use during surgical proceduresinvolving a surgical site having an associated pressure higher thanambient pressure, said system comprising a filter having an outlet side,and a fluid conduit extending between the surgical site and the filter,said fluid conduit defining a fluid flow path between the surgical siteand filter, said higher pressure generating a fluid flow in the fluidflow path at a flow rate of from approximately 0.2 to 20 liters perminute at a pressure drop of from approximately 0.5 to 20 mm Hg from thesite to the outlet side.
 2. The system according to claim 1, the flowrate is approximately 1.8 liters per minute at a pressure drop ofapproximately 2 to 3 mm Hg.
 3. The system according to claim 1, whereinthe flow rate is approximately 3.6 to 3.8 liters/minute at a pressuredrop of approximately 1 mm Hg.
 4. The system of claim 1, furthercomprising a valve located between the filter and the surgical site. 5.The system of claim 4, wherein the valve is operably coupled to thefluid conduit.
 6. The system of claim 5, wherein the valve comprises afluid conduit compressing member.
 7. The system of claim 6, wherein thevalve comprises a housing portion, wherein the conduit compressingmember is movable relative to the housing portion to change the flowrate.